BACKGROUND: Endoscopic ultrasound (EUS) with fine-needle
aspiration (FNA) can characterize and diagnose pancreatic lesions as
malignant, but cannot definitively rule out the presence of malignancy.
Outcome data regarding the length of follow-up in patients
with negative or nondiagnostic EUS-FNA of pancreatic lesions are
not well-established.OBJECTIVE: To determine the long-term outcome and provide follow-up
guidance for patients with negative EUS-FNA diagnosis of suspected
pancreatic lesions based on imaging predictors.METHODS: A retrospective review of patients undergoing EUS-FNA
for suspected pancreatic lesions, but with negative or nondiagnostic
FNA results was conducted at a tertiary care referral medical centre.
Patient demographics, EUS imaging characteristics and follow-up data
were examined.RESULTS: Seventeen of 55 patients (30.9%) with negative/nondiagnostic
FNA were subsequently diagnosed with pancreatic malignancy.
The risk of cancer was significantly higher for patients who had associated
lymph nodes on EUS (P<0.001) and vascular involvement on
EUS (P=0.001). The mean time to diagnosis in the group with falsenegative
EUS-FNA diagnosis was 66 days. The true-negative EUSFNA
patients were followed for a mean of 403 days after negative
EUS-FNA results without the development of malignancy.CONCLUSION: For patients undergoing EUS-FNA for a suspected
pancreatic lesion, a negative or nondiagnostic FNA does not provide
conclusive evidence for the absence of cancer. Patients for whom vascular
invasion and lymphadenopathy are detected on EUS are more
likely to have a true malignant lesion and should be followed closely.
When a patient has been monitored for six months or more with no
cancer being diagnosed, there appears to be much less chance that a
pancreatic malignancy is present.